Adherence and persistence to direct factor Xa inhibitors in the community following newly diagnosed venous thromboembolism: a retrospective pharmacy-linkage study.

OBJECTIVES: To assess adherence and persistence to the direct factor Xa inhibitor oral anticoagulants in the community following newly diagnosed venous thromboembolism (VTE). METHODS: We retrospectively reviewed community pharmacy dispensing data on all patients with newly diagnosed VTE who were prescribed direct factor Xa inhibitors, apixaban or rivaroxaban, between January 2018 and December 2019 at our institution. Proportion of days covered (PDC) was used to assess adherence at 90 days, and 6- and 12 months. Persistence was measured by participants having both dispensed supply of a factor Xa inhibitor at the end of the treatment period and no significant gaps (maximum of 60 days) in supply. KEY FINDINGS: There were 225 patients identified. Overall PDC at 90 days, 6- and 12 months were 84.6%, 86.2% and 86.1%, respectively. Apixaban had a higher mean overall PDC than rivaroxaban (86.2% and 80.6%, respectively). Females demonstrated higher PDC compared with males (87.3% versus 81.2%). Overall, 133 patients (64%) were persistent with therapy. CONCLUSIONS: In patients with newly diagnosed VTE treated with a factor Xa inhibitor, adherence rates are high at >80%, with females and those prescribed apixaban exhibiting higher adherence. These findings may assist clinicians in identifying those patients with VTE at risk of poor adherence.

Improving the rate of inferior vena cava filter retrieval through multidisciplinary engagement.

Background: The placement of retrievable inferior vena cava (IVC) filters occurs commonly, but retrieval rates remain low. Consequently, there is an unmet clinical need to ensure appropriate follow-up and retrieval of these devices. Objectives: To determine the association between an IVC filter surveillance team with filter retrievals or a documented filter plan, time to retrieval, and incidence of filter complications or recurrent venous thromboembolism. Methods: Ambidirectional cohort study evaluating consecutive IVC filter insertions before and after the implementation of a multidisciplinary surveillance team (MDST). We report an odds ratio (OR) with 95% CIs, adjusted by age, sex, weight, and malignancy status. Results: Overall, 453 patients were included, with 272 individuals in the pre-MDST cohort and 181 individuals in the post-MDST cohort. The MDST was associated with a higher composite primary outcome of IVC filter retrieval or a documented filter plan from 79.4% in the pre-MDST cohort to 96.1% in the post-MDST cohort (OR, 6.44; 95% CI, 3.06-15.84). Compared with the pre-MDST cohort, IVC filter retrieval rates were higher in the post-MDST cohort (52.6%-73.5%, respectively; (OR, 2.50; 95% CI, 1.67-3.78). The MDST was associated with a shorter median time-to-filter retrieval (187-150 days, hazard ratio, 1.78; 95% CI, 1.39-2.29), but there was no significant difference when comparing symptomatic or clinically significant IVC filter complications, recurrent venous thromboembolism, or mortality. Conclusion: Our study demonstrates the importance of a structured program to ensure timely IVC filter retrieval and ultimately improve patient care.

High rate of false-positive postoperative venous thromboembolism identified using hospital ICD-10 coding.

The Health Roundtable, a national benchmarking body, identified our institution as an outlier with a high number of postoperative venous thromboembolism (VTE) events. We performed a retrospective study to determine the accuracy of hospital coding for the incidence and severity of postoperative VTE. Of 232 patients identified from ICD-10 coding, 52 (22.4%) were incorrectly coded. Approximately one third (n = 68) of all VTE were asymptomatic, diagnosed incidentally. Thus, coding data are inherently flawed with inaccuracy and overrepresent the true number of VTE events, with a substantial proportion of limited clinical relevance.

Improving compliance with venous thromboembolism prophylaxis guidelines in obese inpatients.

Obesity is a well-recognised risk factor for venous thromboembolism, and increased dosing of pharmacological prophylaxis is recommended in obese inpatients. We performed a clinical decision support intervention by adjusting order sentences of prophylactic enoxaparin within our electronic medical records, which significantly improved appropriate dosing for thromboprophylaxis in obese inpatients at our institution.

Isolated distal DVT in trauma: A study of the management of isolated distal deep vein thrombosis acquired as an inpatient in trauma patients.

BACKGROUND: Isolated distal deep vein thromboses (IDDVT) are common complications of trauma inpatient admission, however their management is controversial. We aimed to analyse outcomes in patients admitted to a level three tertiary referral centre who received therapeutic anticoagulation compared to those that did not. We hypothesised that therapeutic anticoagulation would be safe and effective in trauma inpatients who develop IDDVT. METHODS: We performed a review of the electronic case notes of all patients with venous thromboembolism listed as a complication whilst admitted as an inpatient under the trauma unit at a tertiary institution over a 4-year period, from October 2014 to October 2018. Demographic data was collected, as well as data regarding management, major bleeding and progression of thrombosis to proximal DVT or PE. RESULTS: 91 IDDVT in trauma inpatients were identified. 33 patients received therapeutic anticoagulation within seven days of their diagnosis. No major bleeding was observed in this group, while one episode of thrombus progression was observed. 58 patients were not given therapeutic anticoagulation within seven days of IDDVT diagnosis. There were seven episodes of thrombus progression in this group on median day 5 post diagnosis, while no major bleeding was observed. CONCLUSION: Only approximately 1/3rd of patients with IDDVT after trauma received therapeutic anticoagulation, and in these selected cases it appears safe. Those who did not receive therapeutic anticoagulation had a significant rate of thrombosis extension into the proximal system and pulmonary embolus. Further studies on correctly identifying who can be safely anticoagulated are required and for those who cannot be, these data show more aggressive surveillance and prophylaxis needs to be considered.

Venous thromboembolism in burns patients: Are we underestimating the risk and underdosing our prophylaxis?

BACKGROUND: Burns patients exhibit all factors of Virchow's triad and are thus at high theoretical risk of venous thromboembolism (VTE). At our tertiary referral burns unit, a standard dose of low molecular weight heparin, which acts primarily by inhibiting Factor Xa, is given for thromboprophylaxis. However, the pharmacokinetics of enoxaparin are altered following a burn injury, and thus burns patients are likely underdosed on their thromboprophylaxis. The objectives of this study were to determine the incidence and risk factors for VTE among burns patients at the Victorian Adult Burns Service (VABS) and to determine the adequacy of the current enoxaparin thromboprophylaxis regimen through measurement of anti-factor Xa (AFXa) levels and comparison with established reference ranges. METHODS: This study consisted of two parts. In part 1, the Burns Registry of Australia and New Zealand (BRANZ) was reviewed for cases of VTE in burns patients admitted to the VABS from 2013 - 2018. Part 2 was a prospective study that determined peak and trough AFXa levels in patients admitted to the VABS with >10% total body surface area (TBSA) burns. RESULTS: Part 1. Totally, 1,475 patients were admitted to the VABS between 2013 - 2018. There were 20 cases of VTE (1.36%). Percent TBSA of burn (OR = 1.04, 95% CI: 1.03 - 1.06), full thickness burns (OR = 2.78, 95% CI: 1.15 - 6.73), ICU admission (OR = 15.08, 95% CI: 5.01 - 45.44), mechanical ventilation (OR = 10.62, 95% CI: 4.05 - 27.91), operative procedures (OR = 1.43, 95% CI: 1.29 - 1.59), and a longer hospital stay (OR = 1.05, 95% CI: 1.04 - 1.07) were all associated with an increased VTE risk. Part 2. A total of 20 participants with >10% TBSA burns were recruited to the prospective study. Peak anti Factor Xa (AFXa) levels were measured for all 20 participants with 15% recording an initial prophylactic peak AFXa level within reference range. Upon subsequent measurements, 50% of participants reached a prophylactic peak AFXa level. Trough AFXa levels were measured for 17 participants with no participant recording an initial or subsequent trough AFXa level at or above the prophylactic threshold. CONCLUSION: Our study demonstrates a high incidence of VTE among burns patients at the VABS, especially among the major burns patients, and a thromboprophylaxis protocol that is ineffective in achieving prophylactic levels of AFXa level. The evidence suggests a need to evaluate different dosing protocols among burns patients in order to improve AFXa levels, with the aim of decreasing incidence of VTE in high-risk patients.